JPH03214700A - Manufacture of electronic parts - Google Patents

Abstract

PURPOSE:To correct a part highly accurately at the time of positional correction and also to reduce the parts which are discarded due to unacceptable shape by adding the correction, too, of parallel shift to rotational compensation. CONSTITUTION:The vertical correction angle thetay of an electronic part and the horizontal correction angle thetax are measured. And the dispersion of the lead pitches of the electronic part is corrected by rotating it by the amount of the smaller one between thetax and thetay when the difference between the vertical correction angle thetay and the horizontal correction angle thetax is large, and shifting the electronic part horizontally for the amount of ¦thetax-thetay¦. When performing parts correction this way, in the case that it is the part with dispersion in lead pitches and that the dispersion of the lead pitches exists only on one side, parallel correction is performed besides usual rotational correction. Hereby, those excluding the side where the lead pitches are dispersed and the opposite side can be installed highly accurately, and for opposite both sides, highly accuracies can be maintained, so the quality of a completed board improves, and the parts, which are discarded as defective parts, can also be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing electronic components, such as a semiconductor package, when mounting the electronic components on a printed circuit board or the like.

[Prior Art] When mounting electronic components such as semiconductor packages on printed circuit boards, etc., it is necessary to inspect the components, make corrections, and mount the electronic components on the circuit board in order to eliminate defective products. .

Incidentally, in recent years, mounting machines are required to have higher mounting accuracy.

Hereinafter, the above-described conventional method for correcting electronic components will be described with reference to the drawings.

Figure 6 shows a QFP (quad) that requires recognition correction.
flat package), and there are variations in the lead pitch on side B.

FIG. 2 shows a flowchart of a conventional electronic component correction method, in which variations in lead pitch are corrected only by rotation correction.

[Problems to be Solved by the Invention] However, in the conventional correction method using only rotation correction, only the side B has variations, so the other three sides A
, B, and C, resulting in a problem in that accurate mounting of electronic components is hindered.

The present invention solves the problems of the prior art, and by adding translation correction to rotation correction, in the case of such parts, correction can be made by moving only in the A-C direction,
The purpose is to minimize the effects of variation.

[Means for Solving the Problems] In order to achieve the above object, the present invention consists of the following configuration. That is, the present invention is a method for inspecting and correcting a rectangular packaged electronic component having leads and mounting the electronic component on a circuit board, the method comprising: correcting the electronic component in the vertical direction θy; When the difference between the vertical correction angle θy and the horizontal correction angle θx is large, θ
Rotation is corrected by the smaller of x or θy, and θx
This method of manufacturing an electronic component is characterized in that the electronic component is moved in parallel by one θy1 for correction.

[Function] According to the above configuration of the present invention, when performing component correction, if the component has a variation in lead pitch and the variation in lead pitch is only on one side, parallel movement compensation is performed in addition to normal rotation compensation. Since this is done, the parts other than the side where the lead pitch varies and the opposite side can be installed with high precision.
Since high accuracy can be maintained on both opposing sides, the quality of the completed board is improved, the number of parts that are discarded as defective parts is reduced, and the reliability of the mounting machine is significantly improved.

[Example] Hereinafter, an example of the present invention will be described in more detail with reference to the drawings.

In FIG. 1, 1 is a captured image, and 2 is a QFP image to be recognized and corrected. Note that the captured image is
For example, a CCD (solid-state image sensor) is used.

Hereinafter, the operation of one embodiment of the present invention will be described using FIGS. 1 to 5 (however, FIGS. 2 to 4 are flowcharts).

■ First, move the part onto the camera and capture the image from the camera.

3. Next, after extracting the external shape of the part, detect the leads and import the coordinates of each lead. At this time, sides with large lead variations are memorized.

■ Next, find the average value from the lead coordinates of each side,
Connect the facing sides A-C and B-D, and let P be the intersection point.

■ Next, the line connecting each and the vertical correction angle θ
The difference between y and the correction angle θx in the horizontal direction (θx - θy) is determined.

(2) Next, a rotational correction is applied by the angle θx formed between the horizontal direction and the line A-C connecting the sides that do not include the side B that has the largest variation.

■ Next, if 1θy - θx1〉A, then {(θx+θy
) /2) Apply rotational correction by one θx and end the correction. A is obtained from Figure 5.

In FIG. 5, 3 is a land pattern, 4 is a lead, and this is a supplementary diagram for finding A, where a is the width of the land pattern and B is the lead width of the electronic component.

Assuming that the width of the land pattern 3 is a1 and the width of the lead 4 is b4, the deviation X of the leads at symmetrical positions should satisfy the following equation.

X≦2(a-b) ・・・・・・[I]
If the formula [I] is satisfied, the QFP can be mounted on the land pattern. If the radius of the QFP is r, the deviation of the leads at symmetrical positions can be expressed by the following equation.

x=rtanlθx−θy1 ・Old・・[II] Formula [I
], [I[], 2(a-b)≧rtanlθx−θy l− [III
], only parallel correction is required.

Here, if we set θx-θV = A, then A≦j a
n' {2 (a-b)/r}.

■ Next, if Iθx - θy1<A, r
The correction is performed by moving by tan1θx−θy1/2.

■Finally, end the correction process and move on to the next process.

[Effects of the Invention] As explained above, the present invention measures the vertical correction angle θy and the horizontal correction angle θx of an electronic component, and calculates the variation in the lead pitch of the electronic component by measuring the vertical correction angle θy.
If the difference between θx and horizontal correction angle θx is large, the rotation is corrected by the smaller of θx or θy, and 1θx−
By moving the electronic component in parallel for θy1 and correcting it, by introducing parallel correction information in addition to rotation correction information, the component can be corrected with high precision during position correction. can be achieved.

In addition, expensive QF, which had been discarded due to defective shape,
If P also satisfies the variation range shown in FIG. 5, it will not be discarded, and loss costs due to shape defects will also be reduced.

Therefore, an efficient manufacturing method can be achieved as a whole.

[Brief explanation of drawings]

Fig. 1 is a recognition correction image diagram of an embodiment of the present invention, Fig. 2~
Fig. 4 is a flowchart of an embodiment of the present invention, Fig. 5 is a diagram for calculating a judgment formula for correction in an embodiment of the present invention, and Fig. 6 shows a QFP that requires recognition correction. Figure, -Chart diagram. 1... Captured image, image of P. Figure 7 shows flow 2 of the prior art...QF to be recognized and corrected.

Claims (1)

[Claims] (1) A method of inspecting and correcting a rectangular packaged electronic component having leads and mounting the electronic component on a circuit board, the method comprising: a vertical correction angle θy of the electronic component;
The horizontal correction angle θx is measured, and if the difference between the vertical correction angle θy and the horizontal correction angle θx is large, the variation in the lead pitch of the electronic component is calculated by the smaller of θx or θy. 1. A method of manufacturing an electronic component, comprising performing rotational correction and moving the electronic component in parallel for |θx-θy|.